[derf]

http://tv.gawker.com/#!5788237/watch...-on-late-night

When Stephen Colbert donated $26,000 of Jimmy Fallon's money to charity without permission, Fallon one-upped him by challenging the public to come up with the cash. Our prize? Colbert would sing Rebecca Black's "Friday" on tonight's Late Night.

And sing it he did!

In a rousing performance by any standards, Colbert made good (and then some) on his word this evening. Backed by The Roots, Colbert—in full black tie regalia, natch—began the performance solo, before a giant "Friday"-themed backdrop (flanked by Fallon's house band) was unveiled.

But wait, there's more!

After Colbert took us up to the song's creepy rap solo (performed hilariously by a member of The Roots), a heavily auto-tuned Fallon busted out to sing the infamous, "Yesterday was Thursday. Today it is Friday. We we we so excited, we so excited, we gonna have a ball today. Tomorrow is Saturday, and Sunday comes afterwards" bridge.

Oh, yeah: Taylor Hicks then showed up—armed with a motherf*cking harmonica. The Knicks City Dancers were there, too!

All in all, how bad can that be?

Answer: Not bad in the slightest—because this was EPIC.